High strength aluminum alloy

Details High strength aluminum alloy High strength aluminum alloy

1999-12-22

2001-06-19

Jones, Deborah (Department: 1775)

Stock material or miscellaneous articles

All metal or with adjacent metals

Laterally noncoextensive components

C148S437000, C148S438000, C148S439000, C148S440000, C420S416000, C420S528000, C420S542000, C428S548000

Reexamination Certificate

active

06248453

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an aluminum based alloy having excellent mechanical properties at up to about 300° C.
2. Description of Background Art
Aluminum and aluminum alloys have a combination of good mechanical properties and low density that make them useful for some aerospace applications. However, most prior aluminum alloys have had a maximum use temperature of about 150° C.
Prior attempts to improve the high temperature mechanical properties of aluminum alloys have included the addition of inert particles such as alumina into an aluminum matrix. The inert particles strengthen the alloy and help it to maintain properties at elevated temperatures. However, the benefits obtained in the addition of such particles are limited and such materials have not found widespread application.
Other attempts to improve the mechanical properties of aluminum have focused on the development of stable intermetallic particles in an aluminum matrix by rapid solidification. U.S. Pat. No. 4,647,321 is typical of such alloys. This type of alloy has generally been observed to undergo particle coarsening and resultant loss of mechanical properties during processing.
A limited number of alloys are known which contain the element scandium. One group of such alloys is typified by U.S. Pat. Nos. 4,689,090 and 4,874,440, in which scandium is described as promoting or enhancing superplasticity. Superplasticity is a condition wherein, at elevated temperatures, a material displays unusual amounts of ductility and can be readily formed into complex shapes. Superplasticity is generally regarded as incompatible with elevated temperature strength and stability.
Another patent WO 95/32074 suggests the use of scandium to enhance the weldability of aluminum alloys. Finally, U.S. Pat. No. 5,620,652 mentions the possible small amounts of scandium as grain refinement agents.
Other patents relating to scandium containing aluminum alloys include WO 96/10099.
None of these prior patents appear to suggest the use of scandium in an aluminum alloy for use at elevated temperatures.
SUMMARY OF THE INVENTION
According to the present invention, an aluminum alloy containing a dispersion of particles having L1
2
structure is described. The alloy is processed by rapid solidification. Al
3
Sc is an example of an L1
2
compound which may be dispersed in an aluminum solid solution matrix.
According to the present invention, intentional amounts of other alloying elements are made to modify the lattice parameter of the matrix and/or the Al
3
X L1
2
particulates; the alloying additions are selected in kind and amount so as to render the lattice parameter of the matrix and the particles essentially identical at the intended use temperature.
Both the aluminum solid solution matrix and the Al
3
X particulates have face centered cubic structures, and will be coherent when their respective lattice parameters are matched to within about 1% preferably to within about 0.5%, and most preferably to within about 0.25%. When the condition of substantial coherency is obtained, the particles are highly stable at elevated temperatures, and the mechanical properties of the material will remain high at elevated temperatures.


REFERENCES:
patent: 4259112 (1981-03-01), Dolowy, Jr. et al.
patent: 4463058 (1984-07-01), Hood et al.
patent: 4597792 (1986-07-01), Webster
patent: 4647321 (1987-03-01), Adam
patent: 4689090 (1987-08-01), Sawtell et al.
patent: 4755221 (1988-07-01), Paliwal et al.
patent: 4797155 (1989-01-01), Das
patent: 4865806 (1989-09-01), Skibo et al.
patent: 4874440 (1989-10-01), Sawtell et al.
patent: 5055257 (1991-10-01), Chakrabarti et al.
patent: 5226983 (1993-07-01), Skinner et al.
patent: 5620652 (1997-04-01), Tack et al.
patent: WO 95/32074 (1995-11-01), None
patent: WO 96/10099 (1996-04-01), None

Affiliated with

Also associated with

Rating

High strength aluminum alloy does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with High strength aluminum alloy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High strength aluminum alloy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2492634